Central heating room thermostat fitting

Wurzle_2

Hi, hopefully someone can offer some advice!

I recently had gas central heating fitted (Boiler is a Main 24HE identical to the Baxi 80HE)
I have an external programmer but the only thermostat is on the Boiler itself
and the boiler when on seems to run continously
I want to fit an external room thermostat, just purchased a Horstmann HRT2 bimetalic thermostat it only has 3 connections L=common, Load & Neutral
any ideas how i wire it up, to the programmer or the boiler?

any advice greatfully recived

Wurzle_2

I cant see any diagrams on the site

buglawton

I once moved into a 10 year old house and it had the same arrangement - no wall thermostat - so was boilng hot! Can't understand how the previous owners stood it. I had to get the above mentioned wiring diagrams to intercept the circuit at the right point, ie the radiator circuit control only. A job only for those with an understanding of electrics.

It's pretty outrageous that your installer did not include the wall 'stat - I would call them & ask exactly why - don't they belong to a professional association?

robowen

Did the thermostat not have any wiring instruction ?

Wurzle_2

only guide it gives is:
4=N
3=LOAD (HEAT)
2= DONT USE
1=LINE

ship-badger

The installation manual for the boiler shows how to wire in a room stat. If you dont have the manual you can download it from Baxi's website. On the control circuit board of the boiler will be a short wire linking two of the terminals together. This link is removed and the live and feed wires from the stat are wired in. The neutral from the stat is wired to the neutral on the control board. If you have only just had this boiler installed then tell the installer that under current building regs it is a legal requirement that a room stat (or programmable room stat) be fitted. Then tell him to come and fit it. If he will not do this, threaten to report him to CORGI (he must be a member), that should get his attention. I am a registered installer.

Nile

Hello ship-badger


Welcome to the MSE site.:wave:

moneysavingplumber

How recently was the installation? If it was after April 2005 then the installer would have been obliged under Building Regulation Part L basic practice HC5 to fit a minimum control of room thermostat and timer in conjunction with TRVs on all rads except the one closest to the room thermostat.

On most combis there is a marked terminal block for room thermostat wiring. However, it involves new wiring so would be notifiable to building control under Part P, if you did it yourself you would need to have the work inspected to comply.

EDIT: Sorry just re-read the thread and seen it was already covered :rolleyes: .